But optimizing for those with no development experience isn't one of the goals of React. From the "thinking in react" page in the docs,
"React is, in my opinion, the premier way to build big, fast Web apps with JavaScript."
Nowhere in the documentation does it stress that it's easy to learn or ideal for beginners. If you don't know Javascript, writing React applications (or any application, really) is going to be painful. Full stop. JSX adds cognitive load when writing code, but reduces cognitive load when comparing the DOM to the component that created it. Given the amount of time I spent debugging and refactoring, I'm happy to use JSX.
Consistency is valuable for everyone, particularly when refactoring. You can't refactor JSX according to the rules of JS or the rules of HTML - you have to shift gears to refactor according to the rules of JSX (particularly hard since you're probably refactoring the surrounding JS at the same time). If it's possible to retain the code:dom correspondence with an approach that's based on (and follows the same rules as) vanilla JS - and it sounds like this Hyperscript does that - surely that's an improvement.
Whether or not React's goal is to cater to beginners doesn't make the argument any less valid. Also React doesn't equal JSX. The React docs also mention how to do things without JSX.
Maybe it's the article's title that has understandably rankled some people by seemingly maligning JSX. However, I think it's a very valid concern to have when ramping up a team that's unfamiliar with JS and React.
It doesn't make it less valid, but "is JSX bad" has been done to death. It's been the subject of Medium posts like OP since I started using it in 2014. If you're "ramping up a team that's unfamiliar with JS and React," maybe you should be deciding whether to hire somebody experienced with JS and React instead of deciding whether or not to use JSX.
I'm not in the situation of ramping up a team unfamiliar as the author was. But it sounds like he was experienced with JS and React himself. Or are you suggesting he should replace his team with people more familiar with JS+React?
"React is, in my opinion, the premier way to build big, fast Web apps with JavaScript."
Nowhere in the documentation does it stress that it's easy to learn or ideal for beginners. If you don't know Javascript, writing React applications (or any application, really) is going to be painful. Full stop. JSX adds cognitive load when writing code, but reduces cognitive load when comparing the DOM to the component that created it. Given the amount of time I spent debugging and refactoring, I'm happy to use JSX.